post-12 week scan confused: CVS or not?

HiThis is my first post, I'm 32 and this is my first pregnancy. I'm just looking for any advice/experiences of others here, as I am totally confused after my 12 week scan.

I had my 12 week scan last Wednesday (2nd Jan), basically because of Christmas/NY etc I ended up being scheduled for the scan when I should have been 12w 6d, however the sonographer noted that I was further along than I thought: 13w 5d (almost at the limit for the scan), and measured the baby at almost 80mm in length.

The baby was moving around and she noted that all looked good, but she had a really hard time getting the baby in the correct position for all of the measurements. I ended up having 3 scans, and she was unable to take the measurements at all for the nuchal translucency as the cord was around the baby's neck. They re-booked me in for the next morning, and so I went back for another scan, it was a different sonographer this one also had trouble with getting the baby into position. Eventually she measured the length at 76mm and noted that I was at 13w 4d.

Eventually when she managed to get the NT, she found it was at 2.8mm: just over 95th percentile, however, a radiographer who had come in to help the intern sonographer said that whilst it was high it wasn't worryingly high. When I got the blood results back a day later I was given a 1:189 risk of trisonomy and was offered a CVS or amnio.

I am booked in for CVS on Tuesday (in 2 days), but now I don't know what to do for the best. At first the shock of seeing that we were in the high risk group made me want the CVS straight away, now after looking through all my notes, I feel almost convinced that there is nothing wrong with the baby: I'm sure I can see a nasal bone (a pretty big one!), they didn't pick up anything wrong with the heart or bowel, and on the PAPP-A test my level is 1.82 - which almost put me off the high end of the bell curve for DS. Unfortunately my bHCG levels came out high too, and I suppose that this + the NT has given me a high reading. But then I have no medical training whatsoever and this is all just the result of 48 hours obsessively looking over all my scans and notes and googling every combination of everything I can think of.

I am still a little worried about the risk of T21 etc and I still want to know one way or the other. I don't know yet what I would do, and would have to make a decision based on more facts about how poorly the baby is (e.g. heart, brain, bowel problems), but it's hard to imagine it being sick when all the scans show a perfect little body. It feels weird to trust blindly a number generated by a computer, without weighting many other variables - like human error in measuring the baby, the fact that both my HCG and PAPP-A were both high, the presence of the nasal bone, the fact that I was at the upper end of the time limit etc.

The last day or so I've been getting myself worked up about the miscarriage risk after a CVS, I would feel so so awful if I miscarried a perfectly healthy baby. I feel like I should take the test and my partner/family all think it's a good idea. But it's agonising not knowing what to do for the best, and I can't really focus on anything else at the minute.

Before you have the CVS, you could consider a new blood test instead, called the Harmony Test. It is only available privately unfortunately at one London clinic (The Fetal Medicine Centre), but if the cost and location are an option for you then it would well worth it given your worries about the miscarriage risk. I wrote a full post on here about the test on 5th December, and I know others have talked about it on here too.

Thinking of you, it is such a stressful time. Really hope you have a happy outcome.

I just wanted to share my recent experience and tell you about a new test that might help you if youre worrying about an elevated risk for Downs Syndrome or the other Trisomies, following screening.

I was initially given a 1:46 risk of my baby having Downs Syndrome. This was based mainly on my age (39) and hormones (PAPP-A was low at 0.42 MoM and HCG was high at 1.67 MoM). Everything looked fine on a detailed ultrasound scan, including all the potential markers at 12/13 weeks - a present nasal bone, normal tricuspid flow (heart) and Ductus Venosus (a-wave) positive (liver).

With an elevated risk, I was offered CVS, but have had miscarriages before and really didnt want to take the chance of losing the baby.

After half a day on Google, I discovered that a new, non-invasive test has very recently (October 2012) become available in London - in a private clinic - that can give a more definite answer, without the risk of miscarriage. It is called the Harmony Test and is used in the USA all the time. It involves just a simple blood sample, which is analysed in the lab to look at the cell-free fetal DNA (cfDNA) in the maternal blood and analyses the relative proportion of chromosomes. The consultant told me that it is 99.9% accurate and the false positive rate is less than 0.1%. They do not claim that it is diagnostic in the same way that CVS or Amnio are said to be 100% conclusive, so it is still called a screening test, but the level of accuracy (proven in the States) and the fact that it actually directly analyses the babys DNA have given us the confidence that we will trust the results entirely.

It takes two weeks to get the results (a very long, worrying two weeks!) but we received our amazing news yesterday that the test has come back negative for Trisomy 21 (Downs), Trisomy 18 and Trisomy 13. Our risk, which was originally 1 in 46, is now estimated at less than 1 in 10,000! We are feeling so relieved and so lucky, thats why I felt I just had to tell people that this option is out there.

The test isnt cheap unfortunately, so sadly it isnt going to be a possibility for everyone. We paid £180 for a repeat of the standard combined test with a more detailed scan (blood and combined results were back immediately following the scan, no waiting) and then on top of that it was £400 for the Harmony test (results for that took two weeks). It is a lot of money. We are so fortunate that we can afford it, but I can safely say it was the best £400 I have ever, ever spent. Im aware that the test is in research for the NHS but dont know how soon they will be able to offer it. The test also goes by another name in the States too: MaterniT21.

It is so new to the UK that it doesnt even get a mention on the clinics own web site yet, but this is where to go: The Fetal Medicine Centre, 137 Harley Street, London, W1G 6BG; www.fetalmedicine.com/; +44 (0)20 7486 0476. It is run by Professor Kypros Nicolaides, who as far as I can tell is THE authority on fetal medicine and screening.

Heres the press release that I discovered, which led me to call them: www.prnewswire.co.uk/news-releases/the-fetal-medicine-centre-and-ariosa-diagnostics-partner-to-bring-the-harmony-prenatal-test-to-the-united-kingdom-174715781.html

Good luck and thinking of you if youre in that horrible place having just received an elevated risk from screening. It is so scary, upsetting, confusing and exhausting. Wishing you all the best.

It all rather depends on your mind set I think, there is no 'right' answer... I'm the sort of person that needs to know, and wouldn't be able to put it to the back of my mind and wait it out.

I had a 1:15 result, and all the results were skewed to down syndrome, I had low Papp-a and high HCG and was 35. The nuchal fold was 2.6mm and like yours it was high but not hugely so. No amount of googling put my mind at ease even though the scan looked good so I had a CVS (and the results came back negative for all chromosome disorders).

There are other options open to you at this point. You could investigate the Harmony blood test and see if you could have that done. Or you could wait for the 20 week scan and see if that indicates any structural abnormalities - you could have an amnio at that point if you wanted to?

I can't comment on the Harmony test test but I had a CVS about a month and a half ago which fortunately came back all clear, the proceedure wasn't anywhere near as bad as I expected and though the miscarriage rates quoted make it sound dreadful and there is very definitely a risk these are the stated national levels and it's worth speaking to your screening midwife or whomever you're liasing with to understand the individual record of your consultant.

Personally I'm not sure I could've gone through the remainder of my pregnancy with a "high risk" hanging over me so I felt that a diagnostic test was the right thing but as mummy says only you can know this.

I didn't use them myself but I've heard that Antenatal Results and Choices are a very good provider of advice and support and you can reach them by phone.

DS had an NT of 3.1mm (similar gestation) and I had high hcg and my risk came back as 1:156 which here isn't considered high risk and I was offered no further tests.

Like you, they couldn't get ds into a good position, he wouldn't lie flat and his head was bent. I had to wee 3 times and finally empty my bladder completely. Still couldn't get it perfectly and I suspect his gestation and awkward position skewed the measurements somewhat.

He is 16mo now and absolutely fine.

Just thought it was worth mentioning that here you wouldn't even be high risk.